Enhancement of natural killer (NK) cell proliferation and activity

A method of ex-vivo culturing natural killer (NK) cells, the method comprising culturing a population of cells comprising NK cells with an aryl hydrocarbon receptor (AHR) antagonist, wherein said AHR antagonist is represented by Formula I:

• wherein:
• G1 is selected from N and CR3;
• R3 is selected from hydrogen, C1-4alkyl and biphenyl;
• G2, G3 and G4 are each independently selected from —CH— and N;
• with the proviso that at least one of G3 and G4 is N;
• and with the proviso that G1 and G2 are not both N;
• L is selected from a substituted or unsubstituted alkylamino, a substituted or unsubstituted amino or a substituted or unsubstituted alkyl;
• R1 is selected from hydrogen, a substituted or unsubstituted aryl and a substituted or unsubstituted heteroaryl;
• with the proviso that R1 and R3 are not both hydrogen;
• R2 is selected from —S(O)2NR6aR6b, —NR9aC(O)R9b, —NR6aC(O)NR6bR6c, a substituted or unsubstituted aryl and a substituted or unsubstituted heteroaryl;
• and
• R4 is selected from a substituted or unsubstituted C1-10alkyl, a substituted or unsubstituted C1-10alkenyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted alkaryl, a substituted or unsubstituted heteroalicyclic and a substituted or unsubstituted heteroaryl.